D3 v5 Zoomable Sunburst
This interactive sunburst visualization displays the hierarchical structure of the Flare dataset, with arc size proportional to leaf-node values and color encoding by top-level category. Clicking any arc zooms to that subtree via animated transitions using `d3.transition` and `transition.attrTween`, while an inner circle returns to the root. Built with D3 v5’s `d3.hierarchy`, `d3.partition`, and `d3.arc`, labels rotate to remain readable. Data loads through the Observable standard library’s `require()` method, and rendering uses SVG with `fill-opacity` to indicate parent-child relationships.